package com.supermap.gwfs.datashare.filter;

import java.util.List;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import org.springframework.web.servlet.HandlerInterceptor;
import org.springframework.web.servlet.ModelAndView;

/**  
 * 请求拦截器，处理跨域问题  
 *  
 */  
public class CrossInterceptor implements HandlerInterceptor {  
  
    private List<String> excludedUrls;  
  
    public List<String> getExcludedUrls() {  
        return excludedUrls;  
    }  
  
    public void setExcludedUrls(List<String> excludedUrls) {  
        this.excludedUrls = excludedUrls;  
    }  
  
    /**  
     *   
     * 在业务处理器处理请求之前被调用 如果返回false   
     * 从当前的拦截器往回执行所有拦截器的afterCompletion(),  
     * 再退出拦截器链, 如果返回true 执行下一个拦截器,  
     * 直到所有的拦截器都执行完毕 再执行被拦截的Controller  
     * 然后进入拦截器链,  
     * 从最后一个拦截器往回执行所有的postHandle()  
     * 接着再从最后一个拦截器往回执行所有的afterCompletion()  
     *   
     * @param  request  
     *   
     * @param  response  
     */  
    public boolean preHandle(HttpServletRequest request, HttpServletResponse response,  
            Object handler) throws Exception {  
        response.setHeader("Access-Control-Allow-Origin", "*");  
        response.setHeader("Access-Control-Allow-Methods", "*");  
        response.setHeader("Access-Control-Max-Age", "3600");  
        response.setHeader("Access-Control-Allow-Headers",  
                "Origin, X-Requested-With, Content-Type, Accept");  
        return true;  
    }  
  
    // 在业务处理器处理请求执行完成后,生成视图之前执行的动作  
    public void postHandle(HttpServletRequest request, HttpServletResponse response, Object handler,  
            ModelAndView modelAndView) throws Exception {  
  
    }  
  
    /**  
     *   
     * 在DispatcherServlet完全处理完请求后被调用  
     * 当有拦截器抛出异常时,  
     * 会从当前拦截器往回执行所有的拦截器的afterCompletion()  
     *   
     * @param request  
     *   
     * @param response  
     *   
     * @param handler  
     *   
     */  
    public void afterCompletion(HttpServletRequest request, HttpServletResponse response,  
            Object handler, Exception ex) throws Exception {  
  
    }  
}  
